This will make it so your grub console will require a password to edit the lines, and the recovery modes won't work unless the password is typed. To access the other grub options at the menu, follow the instructions at the bottom of the screen. It will be something like pressing p and typing your password.

How to disable history listing in Console mode

export HISTFILESIZE=4
unset HISTFILE=5
# Change this to a reasonable number of lines to save, I like to save only 100.
export HISTSIZE=1
# Ignores duplicate lines next to each other
export HISTCONTROL=ignoredups

This will disable Bash history for the user, retaining keystroke history and recall to use while limiting recall history to 100 lines. This will also not record duplicate lines next to each other.

What: Quote from Wikipedia: "LoJack is an aftermarket vehicle tracking system that allows cars to be tracked by police after being stolen. The manufacturer claims a 90% recovery rate. The name "LoJack" is a play on the word "hijack," meaning the theft of a vehicle through force."

Why: If your laptop is ever stolen and connected to the Internet. You will be able to find out from what IP it connects to the Internet from and contact the authorities.

How:

Get a free dynamic IP account from one of the many providers. Here we will use DynDNS.